A rubber-tired vehicle transportation system, as described in an article published in the conference record of the 28th IEEE vehicular technology group in relation to a meeting in Denver in March 1978 and entitled Atlanta Airport People Mover, can include a guide beam located in the center of parallel vehicle support tracks, with a power distribution apparatus consisting of five rail members mounted on top of the guide beam and operative with vehicle carried current collector shoes to provide desired propulsion power and control signals to the vehicle. The three top rails distribute three phase AC power, and fourth and fifth rails provide guidance for the main collector shoes as well as a ground for the vehicle system and are used for the provision of speed command signals to control the vehicle and to detect the presence of the vehicle in each of provided track signal blocks. Such a track system can include a movable track switch that operates between the two parallel support tracks and includes at least one movable guide beam with movable power rails. As the track switch moves back and forth between alternate route selection positions, the ends of the movable power, ground and signal rails carried by that switch have to align with cooperating fixed position power, ground and signal rails. It is difficult to cut a given rail into a fixed section and a movable section and expect the alignment of the power rail section ends to occur precisely as the switch guide beam is cooperatively positioned. When the power rail ends are slightly misaligned, this can create a power rail contact surface discontinuity in one or both of the vertical and horizontal directions such that as the collector shoe moves along the power rail contact surface, one rail end sticks out farther than the other rail end. A moving collector shoe can hit this discontinuity at upwards of 25 or 30 miles per hour such that the shoe will sometimes bounce away from the desired coupling with the contact surface of the misaligned power rail. When a shoe moves away from the power rail and does not go back into the desired coupling position with the contact surface of that power rail, this can result in the loss of power to the vehicle propulsion motor and in the shoe causing a phase-to-phase electrical short with one of the other power rails. Also when the collector shoe hits the sharp edge of a misaligned rail end this can damage the typical powder metallurgy shoe made of carbon and copper, which shoe is quite brittle and repeated banging of the shoe in this manner will cause the shoe to fracture and eventually break.
In U.S. Pat. No. 4,168,770, the disclosure of which is incorporated herein by reference, there is shown a power distribution rail arrangement mounted on top of the center guide beam of a roadway track and operative with collector shoes carried by a vehicle moving along that roadway track.
In U.S. Pat. No. 4,090,452, the disclosure of which is incorporated herein by reference, there is shown an example of the track switch here involved. The movable guide beam sections of the track switch are movable between a first position with one movable guide beam coextensive with a fixed guide beam of a first roadway and a second position with another movable guide beam coextensive with the fixed guide beam of that first roadway. The one movable guide beam leads to a second roadway and the other movable guide beam leads to a third roadway.
As the track switch moves between its first and second positions, a significant misalignment of the power, ground and signal rail ends can occur from time to time. When the track switch moves to a different position another alignment problem occurs and this involves mating several power rail surfaces. There are two power rails on one side and one power rail on the other side of each guide beam section plus control signal and ground rails, so there are several rail ends with mating contact surfaces that have to be aligned. One prior art apparatus included a fiberglass miniature ramp provided at the juncture between power rail sections where the moving guide beam section met with the fixed guide beam section of the roadway to reduce the impact of the vehicle carried moving collector shoe hitting any out of alignment rail surface at that location. Another prior art apparatus to help the power collector shoes bridge the resulting rail gaps or misalignments was a small brass miniature ramp with a curved surface at each rail gap, such that when the vehicle carried power collector shoe moved through such a rail gap that was slightly misaligned the miniature ramp would allow the collector shoe to have greater tolerance for smoothly guiding off and then guiding back on the joined power rail ends. When the moving shoe hit this latter curved surface it was found in practice that such a curved end surface for the power rail end ramp was actually detrimental to the operation of the collector shoe more so than was the previous tapered ramp surface.